A roof molding cap attachment structure in which the cap is removably fitted to the roof molding, and a roof molding cap attachment structure in which the cap is fitted to the roof molding so as to be slidable in the longitudinal direction are known. However, these roof molding cap attachment structures have a problem in that the cap may be lost, or it may be impossible to form a slide space in the longitudinal direction. In view of such a situation, a roof molding cap attachment structure in which the cap can be rotate (opened and closed) in the vertical direction has been proposed (see JP-UM-A-6-57749).
The cap structure disclosed in JP-UM-A-6-57749 has a lid and a frame for attaching the lid to a roof molding, wherein the lid has shafts that make a pair and are provided on either side in the longitudinal direction, and the frame has a guide groove for guiding the shaft in the vertical direction. The cap structure disclosed in JP-UM-A-6-57749 has a problem in that the shaft of the lid may unintentionally move downward along the guide groove, whereby the lid may be opened or removed inadvertently.